Text::Levenshtein::Damerau(3pm)

1Text::Levenshtein::DameUrsaeur(3C)ontributed Perl DocumeTnetxatt:i:oLnevenshtein::Damerau(3)
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NAME

6       Text::Levenshtein::Damerau - Damerau Levenshtein edit distance.
7

SYNOPSIS

9               use Text::Levenshtein::Damerau;
10               use warnings;
11               use strict;
12
13               my @targets = ('fuor','xr','fourrrr','fo');
14
15               # Initialize Text::Levenshtein::Damerau object with text to compare against
16               my $tld = Text::Levenshtein::Damerau->new('four');
17
18               print $tld->dld($targets[0]);
19               # prints 1
20
21               my $tld = $tld->dld({ list => \@targets });
22               print $tld->{'fuor'};
23               # prints 1
24
25               print $tld->dld_best_match({ list => \@targets });
26               # prints fuor
27
28               print $tld->dld_best_distance({ list => \@targets });
29               # prints 1
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31
32               # or even more simply
33               use Text::Levenshtein::Damerau qw/edistance/;
34               use warnings;
35               use strict;
36
37               print edistance('Neil','Niel');
38               # prints 1
39

DESCRIPTION

41       Returns the true Damerau Levenshtein edit distance of strings with
42       adjacent transpositions. Useful for fuzzy matching, DNA variation
43       metrics, and fraud detection.
44
45       Defaults to using Pure Perl Text::Levenshtein::Damerau::PP, but has an
46       XS addon Text::Levenshtein::Damerau::XS for massive speed imrovements.
47       Works correctly with utf8 if backend supports it; known to work with
48       "Text::Levenshtein::Damerau::PP" and "Text::Levenshtein::Damerau::XS".
49
50               use utf8;
51               my $tld = Text::Levenshtein::Damerau->new('ⓕⓞⓤⓡ');
52               print $tld->dld('ⓕⓤⓞⓡ');
53               # prints 1
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CONSTRUCTOR

56   new
57       Creates and returns a "Text::Levenshtein::Damerau" object. Takes a
58       scalar with the text (source) you want to compare against.
59
60               my $tld = Text::Levenshtein::Damerau->new('Neil');
61               # Creates a new Text::Levenshtein::Damerau object $tld
62

METHODS

64   $tld->dld
65       Scalar Argument: Takes a string to compare with.
66
67       Returns: an integer representing the edit distance between the source
68       and the passed argument.
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70       Hashref Argument: Takes a hashref containing:
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72       ·   list => \@array (array ref of strings to compare with)
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74       ·   OPTIONAL max_distance => $int (only return results with $int
75           distance or less).
76
77       ·   OPTIONAL backend => 'Some::Module::its_function' Any module that
78           will take 2 arguments and returns an int. If the module fails to
79           load, the function doesn't exist, or the function doesn't return a
80           number when passed 2 strings, then "backend" remains unchanged.
81
82                   # Override defaults and use Text::Levenshtein::Damerau::PP's pp_edistance()
83                   $tld->dld({ list=> \@list, backend => 'Text::Levenshtein::Damerau::PP::pp_edistance');
84
85                   # Override defaults and use Text::Levenshtein::Damerau::XS's xs_edistance()
86                   use Text::Levenshtein::Damerau;
87                   requires Text::Levenshtein::Damerau::XS;
88                   ...
89                   $tld->dld({ list=> \@list, backend => 'Text::Levenshtein::Damerau::XS::xs_edistance');
90
91       Returns: hashref with each word from the passed list as keys, and their
92       edit distance (if less than max_distance, which is unlimited by
93       default).
94
95               my $tld = Text::Levenshtein::Damerau->new('Neil');
96               print $tld->dld( 'Niel' );
97               # prints 1
98
99               #or if you want to check the distance of various items in a list
100
101               my @names_list = ('Niel','Jack');
102               my $tld = Text::Levenshtein::Damerau->new('Neil');
103               my $d_ref = $tld->dld({ list=> \@names_list }); # pass a list, returns a hash ref
104               print $d_ref->{'Niel'}; #prints 1
105               print $d_ref->{'Jack'}; #prints 4
106
107   $tld->dld_best_match
108       Argument: an array reference of strings.
109
110       Returns: the string with the smallest edit distance between the source
111       and the array of strings passed.
112
113       Takes distance of $tld source against every item in @targets, then
114       returns the string of the best match.
115
116               my $tld = Text::Levenshtein::Damerau->new('Neil');
117               my @name_spellings = ('Niel','Neell','KNiel');
118               print $tld->dld_best_match({ list=> \@name_spellings });
119               # prints Niel
120
121   $tld->dld_best_distance
122       Arguments: an array reference of strings.
123
124       Returns: the smallest edit distance between the source and the array
125       reference of strings passed.
126
127       Takes distance of $tld source against every item in the passed array,
128       then returns the smallest edit distance.
129
130               my $tld = Text::Levenshtein::Damerau->new('Neil');
131               my @name_spellings = ('Niel','Neell','KNiel');
132               print $tld->dld_best_distance({ list => \@name_spellings });
133               # prints 1
134

EXPORTABLE METHODS

136   edistance
137       Arguments: source string and target string.
138
139       ·   OPTIONAL 3rd argument int (max distance; only return results with
140           $int distance or less). 0 = unlimited. Default = 0.
141
142       Returns: int that represents the edit distance between the two
143       argument. -1 if max distance is set and reached.
144
145       Wrapper function to take the edit distance between a source and target
146       string. It will attempt to use, in order:
147
148       ·   Text::Levenshtein::Damerau::XS xs_edistance
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150       ·   Text::Levenshtein::Damerau::PP pp_edistance
151
152               use Text::Levenshtein::Damerau qw/edistance/;
153               print edistance('Neil','Niel');
154               # prints 1
155

BUGS

165       Please report bugs to:
166
167       <https://rt.cpan.org/Public/Dist/Display.html?Name=Text-Levenshtein-Damerau>
168

AUTHOR

170       Nick Logan <ug@skunkds.com>
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LICENSE AND COPYRIGHT

173       This library is free software; you can redistribute it and/or modify it
174       under the same terms as Perl itself.
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178perl v5.30.1                      2020-01-30     Text::Levenshtein::Damerau(3)